1. Field of the Disclosure
The disclosure relates to a halogen-resistant film-forming composition which can be used for packaging products containing reactive halogenated compounds, such as chlorinated or brominated water treatment products. More particularly, the disclosure relates to a halogen-resistant film including an acid-stable, water-soluble polyvinyl alcohol polymer, an oxidizable organic material, a chelating agent, and a free radical scavenger.
2. Brief Description of Related Technology
One of the many applications of the unit dose packaging concept employing water-soluble films is the packaging of water treatment products, in particular those that contain available chlorine and bromine. This configuration facilitates water treatment processes by allowing the contained chemical (including the packaging film) to be incorporated into the process without the need for opening and disposing of the packaging film. For example, a film package containing a swimming pool sanitizing chemical may be added directly to the pool water in the pool's water treatment system.
While the use of water-soluble films is convenient in applications using these types of reactive halogenated chemicals, prior water-soluble films exhibit compatibility limitations when placed in contact with them. For example, contact with chlorinated and brominated chemicals containing available chlorine and bromine for as little as a week can discolor a non-resistant film and impair its solubility characteristics. Specifically, the films may become soluble in hot water only (i.e., as opposed to being soluble in hot and cold water), or may even become altogether insoluble in water.